JPH0341431A - Copying machine with original size detecting device - Google Patents

Abstract

PURPOSE:To simplify the constitution of a sensor and to ensure size detection by installing plural original sensors, which correspond with original sizes, below a platen glass. CONSTITUTION:In this copying machine, the plural original sensors S1-S4 are arranged below the platen glass 4 in the position where the movement of a scanning carriage 5 is not interrupted; a copying process is performed based on a detected original-size when the platen cover 7 is closed or a copying start button is depressed. The original sizes are discriminated in such a manner that when all the sensors S1-S4 are outputted, the original size is A3; only the sensors S2-S4, the original size B4; only the sensors S3 and S4, the original size A3; and only the sensor S4, the original size B5.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a copying machine equipped with a document size detection device.
In particular, the present invention relates to a copying machine that detects the document size from below the platen glass.

[Conventional technology]

In a general copying machine, the user selects the paper size according to the size of the document to be copied, and then performs the copying operation. On the other hand, in recent years, the size of the original has been detected and the paper of the size corresponding to the original size has been automatically selected and fed, or the copy magnification has been automatically changed by one to match the size of the original. 2. Description of the Related Art Copying machines equipped with automatic document size detection devices have been developed in order to copy onto paper of a constant size regardless of size.

In a copying machine equipped with this automatic document size detection device, for example, a plurality of reflective optical sensors are installed on the back side of the platen cover that covers the platen glass so that the platen glass can be opened and closed. The size of the original is being detected.

However, the back side of the platen cover should originally be a uniform white color, and if an optical sensor is installed, the shape of the optical sensor will be copied when copying thin or small-sized originals, resulting in the image being distorted. It may become dirty.

Furthermore, in recent years, in order to automate copying operations, an automatic document feeder integrated with the platen cover is sometimes provided. In this case, since the white conveyor belt contacts the platen glass, the optical sensor cannot be provided on the platen cover side.

Therefore, in a copying machine equipped with an automatic document feeder,
An optical sensor is attached to a scanning carriage movably provided below the platen glass, and a preliminary scan is performed to detect the size of the original before the original is exposed and scanned.

[Problem to be solved by the invention]

However, attaching the optical sensor to a moving scanning carriage requires complicated wiring and poses reliability problems. Further, performing preliminary scanning to detect the document size not only increases the time required for copying, but also causes the problem that the circuit or program for controlling the movement of the scanning carriage becomes complicated.

Therefore, it is possible to detect the size and orientation of the document tray by disposing a reflective optical sensor S5 below the platen glass 21 and determining the amount of light reflected from the document tray, as shown in FIG. .

That is, as shown in FIG. 7(1), light from a light emitting element Ssa consisting of a lamp or the like is irradiated onto the platen glass 21 through an irradiation slit 22a formed in the slit member 22. As shown in FIG. 7(a), this irradiation range A is positioned on a line that connects approximately the upper right corner of the original tray when originals of various sizes are placed horizontally on the platen glass 21. . A light receiving slit 22b formed in the slit member 22 receives the reflected light from the original document.
A light receiving element Ss consisting of a phototransistor etc.
Light is received at b. The amount of light reflected on the document tray changes depending on the size and orientation of the document tray, and the relationship between the amount of light T received by the light receiving element Ssb and the output voltage V is as shown in FIG.

In other words, the amount of received light I is for A4 size vertically placed, 85th size A4 size,
The number increases in the order of 84 edition and A3 edition. However, the platen glass 21 is capable of placing a maximum of A3-sized originals placed horizontally, and documents placed horizontally are standard.

Therefore, by determining the amount of light I received by the light receiving element SSb, the size and orientation of the document can be detected.

However, when the platen cover 23 is closed, it is difficult to distinguish between the white frame portion of the document tray itself and the white reflective surface of the platen cover 23, making it impossible to accurately detect the document size. In addition, the color of the platen cover 23 can be set to a color such as yellow that can be distinguished by an optical sensor but does not make a difference on the electrostatic latent image on the photoreceptor, but the operation in the case of colored originals is difficult. There were problems such as uncertainty and limitations on the characteristics of the photoreceptor.

The present invention was devised to solve the above problems, and an object of the present invention is to reliably detect the size of a document from the lower side of the platen cover with a simple configuration.

[Means to solve the problem]

In order to achieve the above object, a copying machine equipped with a document size detection device of the present invention is provided with a plurality of document sensors for detecting the size of the document at fixed positions below the platen glass, and in which the platen glass can be opened and closed freely. A platen cover sensor is provided to detect an open/closed state of a covering platen cover, and when the platen cover changes from an open state to a closed state,
Alternatively, the present invention is characterized in that various automatic function processes are performed based on the document size detected by the document sensor when a copy start button instructing the start of a copying operation is pressed.

The various automatic function processes include automatic paper selection and automatic magnification selection.

[Effect]

In the present invention, a document sensor is arranged below the platen glass in accordance with the size of the document, and this document sensor constantly detects the size of the document placed on the platen glass. Then, the document size detected when the platen cover is closed or the copy start button is pressed is determined as the final document size.

Therefore, when copying not only thin originals but also thick originals such as books for which it is difficult to close the platen cover, the original size can be accurately detected, and based on this original size, paper selection, magnification selection, etc. Various automatic processes can be performed.

〔Example〕

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, features of the present invention will be specifically described based on examples with reference to the drawings.

FIG. 1 is a schematic diagram showing a copying machine equipped with a document size detection device of the present invention, and FIG. 2 is a schematic diagram showing the top surface of the copying machine with the platen cover removed.

The copying machine main body 1 is composed of an exposure scanning optical section 2 that scans a document while exposing it to light, and an image forming section 3 that outputs an image onto paper based on the document light from the exposure scanning optical section 2. .

The exposure scanning optical section 2 is disposed below a platen glass 4 provided on the top surface of the copying machine main body 1, and, as is well known, is equipped with an exposure lamp 1, a scanning carriage 5 consisting of a mirror, a lens, etc. By moving this scanning carriage 5 in synchronization with the rotation of a photoreceptor 6 provided in the image forming section 3, an electrostatic latent image corresponding to the original image is formed on the photoreceptor 6. Note that this electrostatic latent image is subjected to development, transfer, and fixing processes by a well-known electrophotographic process to obtain a copy image on paper.

Furthermore, a plurality of document sensors S, -S for detecting the size of the document placed on the platen glass 4 are arranged below the platen glass 4 and at a position that does not obstruct the movement of the scanning carriage 5. ing. In the case of this example, B5
．． A4. B4. In order to distinguish between the four types of A3 size originals, in Figure 2, when the original is placed horizontally with the lower left corner of the platen glass 4 as the reference position, the upper edge of the A3 size original (indicated by a broken line) The first document sensor S1 is placed slightly inside the upper edge of the B4 size document (indicated by the dashed line), and the second document sensor S2 is placed slightly inside the upper edge of the B4 size document (indicated by the dashed double dotted line). A third document sensor S3 is arranged slightly inside the right edge of the B5 size document (indicated by a solid line), and a fourth document sensor S4 is arranged slightly inside the right edge of the B5 size document (indicated by a solid line).

Each of these four document sensors S1 to S, as represented by the reference numeral S in FIG. When a document is placed in front of the document sensor S, light from the light emitting device S is reflected by the document and enters the photodetector Sc. By doing so, the presence or absence of paper at the position where the document sensor S is placed is determined.

As mentioned above, these document sensors S, ~S, are arranged at multiple locations depending on the size of the document, so the document sensor 5l-34 can detect the document by determining the combination of output and non-output of each document sensor 5l-34. The size can be detected. That is, when there are all outputs from document sensors S+ to S4, the size of the document is A3, and similarly, when only outputs from document sensors S2 to S4 are present, the size of the document is B4, and document size is B4, and document size is B4 when there is only output from document sensors S2 to S4. When outputting only B4, A3, document sensor S,
It can be seen that it is B5 when only the output is .

Further, a platen cover 7 is provided on the top surface of the copying machine main body 1 so as to cover the platen glass 4 so as to be openable and closable via a pivot joint 8. Near the platen cover pivot joint 8 of the copy machine main body 1, there are A platen cover sensor 9 is provided, and its actuator 9a is pushed by a part of the platen cover 7 to detect whether the platen cover 7 is open or closed.

Next, a block diagram of a control circuit for controlling the operation of the copying machine based on the outputs of the above-mentioned sensors will be explained with reference to FIG.

The outputs of each of the document sensors S and -S are supplied to a microcomputer 10 that controls the entire copying machine. This microcomputer 10 includes operation keys 12 provided on the operation panel 11 of the copying machine shown in FIG.
The output from Furthermore, a mode switching button 12e is provided for switching the selection of paper and magnification between automatic and manual. For example, each time the mode switching button 12e is pressed - times, the operation mode is switched cyclically in the order of manual, automatic paper selection, and automatic magnification selection 9 manual.

The operation panel 11 also includes a sheet number display section 13a for displaying the set number of sheets and the number of copies, and a paper size display section 13.
A display section 13 consisting of a C1 magnification display section 13d and the like is provided, and the microcomputer 10 performs a display according to the setting state of the copying machine.

Further, there is also a scanning carriage 59 provided in the exposure scanning optical section 2, a photoreceptor 6 provided in the image processing section 3, and a copying mechanism control device 14 for controlling a developing device, a transfer peeling device, a developing device, etc. (not shown). It is controlled by a microcomputer 10. Further, a lens position control device 15 for moving the lens provided in the exposure scanning optical section 2 according to the copying magnification, and a paper selection device for selecting and feeding paper of a predetermined size from among a plurality of paper sizes. Device 16 is also controlled by microcomputer 10.

Next, the operation of the above-mentioned copying machine will be explained with reference to the flowchart shown in FIG.

Now, as an initial condition, it is assumed that the copying machine is in a rest state, the platen cover 7 is open, and no original is placed. It is also assumed that the operation mode of the copying machine is automatic paper selection mode.

Therefore, the process shown in FIG.
Proceeding to step 102, each document sensor S, ~S4
The document size is detected by the microcomputer 10 based on the output. The process then passes through step 103 to step 104, automatic function processing. The automatic function process automatically selects the copy magnification or paper according to the detected document size, and a flowchart of this process is shown in FIG.

As mentioned above, the copying machine is set to the automatic paper selection mode and there is no original, so the automatic function processing proceeds from steps 201 to 202 and 203 to select priority paper of a predetermined size. For example, the most frequently used A4 size paper is selected.

The display section 13 is controlled according to this paper selection, and the selected paper size 1 is displayed on the paper size display section 13C (step 204). The automatic function processing ends up to this step.

From the automatic function processing in step 104, step 105
After that, the process returns to step 101, and the process described above is repeated while waiting for input from each sensor.

Next, when a B5 size document, for example, is placed on the platen glass 4, the process proceeds from step 202 to step 205 in the flowchart of FIG. A paper size is selected and the display is changed in step 204.

Next, when the platen cover 7 is closed, this is detected by the platen cover sensor 9, and the process jumps from step 101 to step 103, and the data immediately before closing the platen cover 7 is set in the microcomputer 10 as the document size. Stored in memory etc. At this time, the platen cover 7 is placed against the platen glass 4.
For example, if the platen cover sensor 9 is set to turn on when the platen cover 7 approaches 15 degrees,
The document size can be accurately detected before the document is completely closed, that is, in a state where there is a difference in the reflectance of light seen from the document sensors S1 to S4 between the document and other areas.

Next, set the number of copies using the numeric keypad 12a.
The set number of sheets is displayed on the sheet number display section 13a. At this stage, steps 101.103.104.105.10
1 and waits for the copy start button 12b to be pressed.

Next, when the copy start button 12b is pressed, step 10
The process proceeds from step 5 to step 106, where it is determined whether or not the movement of the lens has ended. In this case, since there is no movement of the lens, the process proceeds to step 107, and the copying mechanism control device 14 starts the copying operation. That is, an image of a B5 size document is copied and output on a sheet of the same size, that is, B5 size. During this copying operation, data indicating that the copying machine is in the process of copying is sent from the copying mechanism control device 4 to the microcomputer 10.

During this copying process, the process proceeds from step 103 to step 108, where it is determined whether it is possible to start re-copying, and if it is possible to start re-copying, it is determined whether the start copying button is on (step 109). ), if it is on, automatic function processing similar to step 104 is performed (step 11O). That is, even during the copying process, the photoreceptor 6
If a new electrostatic latent image can be formed on the paper, for example, if the paper after transfer is passing through the fixing device, the next press of the copy start button 12b can be accepted, which improves copy efficiency. We make decisions like this for the sake of improvement.

Next, the operation when the copying machine is set to automatic magnification selection mode will be described. Here, it is assumed that the original size is B5 and the specified paper size is A4.

Steps 101 to 103 are the same as the automatic paper selection mode, but in the automatic magnification selection mode, as shown in FIG. 5 (1)
In the automatic function processing (corresponding to step 104) shown in ), the process advances from step 201 to steps 206 and 207, and the presence or absence of a document is determined. If there is no original, 100% is set as the initial value of the copy magnification (step 208).

If there is a document, the size of the document is B5 and the specified paper size is A4, so the copy magnification is 100.
% to 115% (step 209), and the corresponding magnification is displayed on the magnification display section 13d (step 210). If the copying magnification is changed, the lens is moved by the lens position control device 15 after waiting for a certain period of time, for example, 1.2 seconds (step 212) (step 213). In addition,
The purpose of waiting in step 212 is to prevent the lens from frequently moving during the process of placing the original on the platen glass 4. That is,
Even if the size of the document is B5, when the document is placed on the platen glass 4, it will pass over the document sensors other than the fourth document sensor S, so the document of a different size each time will be placed on the platen glass 4. If so, it will be falsely detected.

If the lens is moved every time a change in magnification is detected, the lens will move frequently each time a document is placed on the platen glass 4, causing an eyesore or an annoying operating sound. do. Furthermore, if the direction of movement of the lens 5 is opposite to the direction corresponding to the actual document size, it takes more time. For this reason, even if there is a change in magnification, the lens is not moved until a certain period of time has elapsed.

When the automatic function processing in step 104 is completed, step 1
05, and if the copy start button 12b is on and the movement of the lens has been completed (step 106), copy processing is performed (step 107). That is, a B5 size document is enlarged and copied onto A4 size paper.

In the flowchart shown in FIG.
1, 102, while the platen cover 7 is open, the document size is constantly detected and stored, and when the platen cover 7 is closed, the document size detection is stopped and the document size is finally obtained. We are trying to use the data obtained.

Therefore, the data when the platen cover 7 is closed is stored as the document size, and automatic function processing is performed based on this data.

6 In the above explanation, copying starts after placing the original on the platen glass 4 and closing the platen cover 7.
2b is turned on, the following describes the operation when the copy start button 12b is turned on with a document placed on the platen glass 4 and the platen cover 7 left open.

In this case, until the copy start button 12b is turned on,
Step IOL 102.103.104.105.1
01, and based on the document size detected in step 102, automatic paper selection or automatic magnification selection is performed in the automatic processing function of step 104.

Then, when the copy start button 12b is turned on, the process advances from step 105 to steps 106 and 107, and copy processing is performed. - Once the copy start button 12b is pressed, the process proceeds from step 103 to step 108, and steps 109 and 110 until it becomes possible to copy again.
is skipped, so the automatic function processing of steps 104 or 110 is not performed. Therefore, when the copy start button 12b is turned on, step 10 is executed immediately before the copy start button 12b is turned on.
Automatic function processing is performed based on the document size detected in step 2. In other words, the document size detected by the document sensor when the copy start button 12b is turned on is used as the document size for the automatic processing function.

As a result, even when copying a thick book or the like in which the platen cover 7 cannot be closed, the size of the original is detected and the paper or magnification is automatically selected for copying. becomes possible.

〔Effect of the invention〕

In the present invention, the document size detected when the platen cover is closed or the copy start button is pressed is regarded as the size of the document to be copied, and automatic paper selection and automatic magnification are performed. Performs automatic function processing such as selection. Thereby, when detecting the size of the document from below the platen glass, the size of the document on the platen glass can be accurately detected even with a fixed document sensor having a simple structure.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing a copying machine equipped with the document size detection device of the present invention, Fig. 2 is a schematic diagram showing the top surface of the copying machine excluding the platen cover, and Fig. 3 is a schematic cross-sectional view of the document sensor. , FIG. 4 is a block diagram of a control circuit for controlling the operation of the copying machine, FIG. 5 is a flowchart for explaining the operation of the copying machine, and FIG. 6 is a schematic diagram of an example of a conventional document size detection device. 7(a) and 7(b) are plan views and cross-sectional views for explaining the operation of the original size detecting device, and FIG. 8 shows the document size and amount of reflected light in the same document size detecting device. It is a graph showing the relationship. 1° Copying machine body 2: Exposure scanning optical section 3: Image forming section 4 Nibraten glass 5: Scanning carriage 6:
Photoreceptor 7: Platen cover 8: Pivot part 9 Ni platen cover sensor 9a: Actuator 10: Microcomputer 1
1: Operation panel 12: Operation key 9 12a: Numeric keypad 12b, copy start button 12c
:Paper size selection button 12d :Magnification selection button 12e:Mode switching button 13:Display section 13a:Number of sheets display section 13bDual magnification display section 13c:Paper size display section 13d:Magnification display section 14:Copying mechanism control device 15:Lens position Control device 16: Paper selection device S, S, ~S,: Original sensor Sa mini block Sb: Light emitting element SC,: Light receiving element

Claims (1)

[Claims] 1. A plurality of document sensors are provided at fixed positions below the platen glass to detect the size of the document, and a platen cover sensor is provided to detect the open/closed state of the platen cover which covers the platen glass so as to be openable and closable. and perform various automatic function processing based on the document size detected by the document sensor when the platen cover changes from an open state to a closed state or when a copy start button that instructs to start a copying operation is pressed. A copying machine equipped with a document size detection device. 2. A copying machine equipped with a document size detection device according to claim 1, wherein the various automatic function processes are automatic paper selection or automatic magnification selection.